1. Field of the Invention
The present invention relates to an information reproducing apparatus for reproducing digital information recorded in a recording medium.
2. Related Background Art
FIG. 1 is a drawing to schematically show a conventional information reproducing apparatus. In the drawing a reproduction signal is a signal read out of a recording medium such as an optical disk, which is compared with a predetermined slice level in a comparator 101 to produce a binary signal. The obtained binary signal is output to a data separator 102, where the binary signal is synchronized with a data clock to produce reproduction data.
FIGS. 2A to 2E are drawings to show waveforms of the signals in the respective portions in FIG. 1, in which FIG. 2B shows the reproduction signal. It is assumed here that recording data as shown in FIG. 2A has been recorded in the recording medium, and reproduction of the recording data gives the reproduction signal as shown in FIG. 2B. When this reproduction signal is put into the comparator 101 to binarize it with the slice level, the binary signal as shown in FIG. 2C is produced. Further, synchronizing the binary signal with the data clock shown in FIG. 2D in the data separator 102, the reproduction data shown in FIG. 2E can be obtained.
The above, conventional information reproducing apparatus, however, had such a problem that the frequency of the data clock became higher with an increase in density of recorded information or with an increase in transfer rate, which narrowed the width of a detection window (a period of a data clock), reducing the error rate and in turn resulting in failing to assure reliability of information reproduction.
The present invention has been accomplished in view of the above problem, and an object of the present invention is to provide an information reproducing apparatus which is free of a reduction in error rate even with an increase in density of information or with an increase in transfer rate, thus assuring the reliability.